Sonic multistage pump

ABSTRACT

An electrohydraulic multistage pump is composed of a series of stages, each stage being connected to the next stage so that when an electric pulse is applied in a stage, fluid is displaced into a succeeding stage and at this time, an electric spark passes across the arc gap to augment the pressure in the succeeding stage. The stages are arced at proper times so that the arc occurs when each stage is under pressure from the sonic wave actuated or caused by the preceding stage. A considerable pressure is developed at the output by the series of electrical pulses operating to raise the pressure in successive stages.

United States Patent [72] Inventor [54] SONIC MULTISTAGE PUMP 3,266,4388/1966 Sauage 103/255 3,267,780 8/1966 Roth i 0 1 103/1 (X) 3,398,6868/1968 Guin 103/1 2,578,145 10/1946 Mi1ler.... 123/32 3,270,688 9/1966Skogg 103/255 3,427,978 2/1969 Hanneman et a1 103/1 FORElGN PATENTS449,752 7/1948 Canada 103/1 858,930 10/1940 France 103/252 PrimaryExaminer-William L. Freeh Attorneys-Americus Mitchell, Joseph E. Kerwinand William A. Dittmann ABSTRACT: An electrohydraulic multistage pump iscomposed of a series of stages, each stage being connected to the nextstage so that when an electric pulse is applied in a stage, fluid isdisplaced into a succeeding stage and at this time, an electric sparkpasses across the arc gap to augment the pressure in the succeedingstage. The stages are arced at proper times so that the arc occurs wheneach stage is under pressure from the sonic wave actuated or caused bythe preceding stage. A considerable pressure is developed at the outputby the series of electrical pulses operating to raise the pressure insuccessive stages.

PATENTED Juuaa m1 SHEET 1 BF 4 ,RESERVOIR HtSERVOlR I N VE N TOR PAUL M.E RL A NDSON ATT'Y.

PATENTEI] M22197: 3.588461 sum 2 OF 4 I N VEN TOR PAUL M. E RLANDSONATT' Y.

PATENTH] M22 I971 SHEET 3 OF 4 SYNC. SIGNAL PULSE GENERATOR TAPPED DELAYLINE SUPPLY MAIN POWER INVENTOR RESERVOIR ATT' Y.

INVENTOR PM T Y T SHEET 0F 4 PATENTEU M22 I971 PULSE GENERATOR PULSEGENERATORv PAUL M. ERLANDSON ATT'Y INPUT SONIC MULTISTAGE PUMP Myinvention is drawn to an electrohydraulic pump for fluids andparticularly to an electrohydraulic multistage pump or piezoelectricpump for furnishing a high-velocity fluid jet of extremely highpressure.

The development of electrohydraulic pumps has led to numerous schemesfor utilizing the expansion of a liquid or gas when a pair of electrodesare supported by a housing and are placed within a pump chamber and aspark arcs across the electrodes to expand the fluid in the chamber.Check valves are placed at each end of the chamber to allowunidirectional flow of fluid through the chamber. Such a system is shownin the patent to R. C. Smith, U.S. Pat. No. 3,185,106 with a chamberwith entrance ports and exit ports and suitable valves for entrance andexit of fluid to the chamber. A pair of electrodes are mounted in thechamber walls. Fairly high pressure is produced in this type ofelectrohydraulic pump. However, there is some debris from the electrodeswhich comes into the fluid and the pressure increase and rate of flow isnot especially larger. Similarly, the patent to C. I... Stec, US. Pat.No. 3,1 50,582, shows an electric pump which utilizes the differentialexpansion of piezoelectric spheres to develop a fluid flow through achamber. This application is subject to the same limitations discussedabove in regard to the patent to R. C. Smith.

It is an object of my present invention to obtain a high-pressure jetpump capable of delivering a volume of fluid.

It is another object of my invention to show an apparatus having amultistage high-velocity jet pump.

It is still another object of my invention to show a machine having longlife and low maintenance for obtaining high-pressure jets.

A further object of my invention is to provide large impulses of powerfrom a power supply without the necessity of drawing large peak currentsfrom a primary supply, such as a utility company powerline, a battery,or other means.

Another object of my invention is to provide sequential impulses ofelectrical energy form a primary supply to storage elements, during alarge portion of each cycle, such that large impulses of power areavailable during the relatively shorter output portion of the cyclewithout necessitating the drawing of large peak currents from theprimary supply.

Another object of this invention is to provide an accurately timedseries of electrical energy impulses to multiple devices which functionin a cooperative manner to produce an end result.

A further objective of this invention is to provide sequential pulses ofelectrical energy to one or more devices, the total energy beingapproximately equivalent to a single pulse of like amplitude whoseduration equals the combined duration of the sequential pulses, buteliminating the disruptive effect of the single pulse upon the energytransfer mechanism.

It is a final object of my invention to define a machine having a highefficiency and high controllability of pressure and jet velocity.

In brief, my invention is an electrohydraulic multistage pump having aseries of stages, each adapted to give its impulse in a predeterminedsequence. Each stage is composed of an electrohydraulic pump, and eachpump is fired by timedelay circuits at such a time as its developedpressure is added to the pressure wave form the preceeding stage. Inthis way, by firing each pump when the maximum pressure wave form thepreceding stage has arrived in the pump chamber, the additional pressurecauses the pressure inside this stage to step up and this pressure istransmitted into the succeeding stage where the same cycle takes place.By repeated application of this cycle, a high-pressure, high-velocityjet is obtained.

The foregoing and other objects and advantages will appear more fullyhereinafter from consideration of the description which follows, takentogether with the drawings. It is understood, however, that the drawingsare for illustration purposes only, and do not define the limits of theinvention.

FIG. 1 shows a schematic drawing of the multistage pump and anelectrically controlled circuit for firing the arcs.

FIG. 2 shows a schematic view as in FIG. 1, but not using the diaphragm.

FIG. 3 shows an individual arc pump with reed valves.

FIG. 4 shows the individual arc pump with ball check valves.

FIG. 5 shows a cross-sectional view of a single cell taken along line4-4 of FIG. 1.

FIG. 6 shows a cross-sectional view of a piezoelectric pump.

FIG. 7 shows a schematic diagram of an electric switching power supplyfor arcs in each cell.

FIG. 8 shows a detailed diagram of portions of the schematic diagram ofFIG. 7.

FIG. 9 shows the L-C circuit of a delay line.

FIG. 1 shows three pump stages connected in series. Each of the seriesof stages generates a certain amount of velocity and pressure. Each pumpconsists of a chamber housing 1 which may be cylindrical, conical or anyother desired shape. A flexible diaphragm 2 is stretched across thechamber to form two compartments. One compartment 3 of the chamber isfilled with a fluid which is conducted into the compartment through aconduit 4 to a flap valve in the side of the chamber 1. The othercompartment 5 formed by the flexible diaphragm 2 is filled by a liquid 6having a fairly high dielectric constant with a sharp electricalbreakdown point when the electrical potential across the liquid reachesa certain voltage. Mercury of transformer oil, for example, arematerials of this sort. A conductive liquid can also be used. Twoelectrodes 7, 8 are mounted in insulators 9, l0 and extend throughopenings in the side of the wall and are spaced apart so that a sparkmay arc from one electrode to the other. When the spark arcs across thegap, the volume occupied by the mercury, for example, is tremendouslyexpanded and the flexible diaphragm 2 moves upward to cause a decreasein the size of the chamber above the diaphragm. Fluid is forced outthrough a one-way valve on the right of the chamber.

The three chambers shown are lined in series and movement of the more orless incompressible fluid in one of the chambers causes movement in thenext chamber. A sharp impact is imparted by the flexible diaphragm 2 tothe pressuretransmitting liquid 11 in the other compartment of thechamber. Thus, when this sharp impact comes through the flexiblediaphragm 2, a pressure wave is produced in the first chamber which istransmitted to the second chamber. At the time that the pressure wavearrives in the second chamber, the pressure in the second chamber isappreciably higher than before the arrival of the pressure wave, and atthis same time, a second pressure is induced in'the second chamber bythe firing of the second set of electrodes in a similar manner to theoperation in the first chamber. A more or less double pressure wave isnow transmitted to the third chamber and simultaneously with thepressure wave arrival in the third chamber, its electrodes fire toheighten the pressure one more step. Therefore, as the pressure wavetravels down the stages, it can be built up to considerable heights ofpressure. Any number of stages may be used to develop pressure dependingon the pressure to be obtained. Suitable power supplies are attached toeach stage for supplying the high voltage and amperage necessary tocause an arc. Similarly, also because some gas and debris may accumulateafter some arcings, and each arcing may consume some liquid, a smallamount of the liquid is forced into the firing chamber 5 by a pump 12and the debris and residual materials are taken out across the top ofthe lower compartment 5 to a sump 13 for possible purification andrecirculation. Each power source is tripped by a single master control.A master control timer is set to fire synchronously for the speed ofpropagation of the sonic wave in whatever liquid is passing through thestages of the pump. This arrangement gives a sonic pump which deliversliquid at very high pressures and relatively small volumes of flow.

In order for a high-intensity pressure wave to be generated andtransmitted down the series, fluid in the pressure-transmitting chamberand connecting conduits must have a relatively high modulus ofelasticity. Mounting a diaphragm between the explosion chamber and thetransmitting chamber avoids contamination of the pressure liquid bydebris which may be left over from the explosion of thepressure-transmitting liquid.

A piezoelectric pump such as that shown in the patent to C. L. Stec, US.Pat. No. 3,150,592, previously referred to, can be used at each stage toprovide a pressure increase or volume-changing element of the pump. Anexample of a piezoelectric pump suitable for use in my present apparatusis shown in FIG. 6 of my drawings. A piezoelectric pump can be used as apumping stage in the same manner as the pumping stages shown in FIG. 1.

FIG. 2 shows a series of pumping stages I4l6 using no flexiblediaphragm. In the situation where particular purity of the flowingpressure liquid is not necessary, the flexible diaphragm may beeliminated. In this case, waste material is taken but by the flowingliquid. Operation of this device is in all essentials the same asdescribed above in reference to the embodiment of FIG. 1.

A variety of valves have response times rapid enough for use with myinvention. Such a valve is a reed valve l7, 18 shown in FIG. 3. A ballcheck valve 19, 20 arrangement is shown in FIG. 4.

To aid in the visualization of a possible embodiment of my invention,FIG. shows the cross section taken along line 5-5 of FIG. I. In thisembodiment, the flexible membrane 2 is shown of a thickness sufficientmerely to act as a barrier between the two liquids involved.

FIG. 6 shows a piezoelectric stage which may be used in place of eachstage shown in FIG. I. A hollow metal sphere 21 has a hollowpiezoelectric sphere 22 inside of it. Ball check valves 23, 24 aremounted at the entrance and exit of the cavity. If a piezoelectric stageis used, it is not necessary to use banks of capacitors to store theelectric current since the amount of current needed to activate apiezoelectric pump is relatively small. The timing device is set to theessential timing necessary to add the piezoelectric pressure to thepressure of the pressure wave as it travels through each of thecompartments.

Various advantages accrue to this apparatus. For example, highefficiency, very high pressure, quiet operation, relative compaction,and low cost.

It is anticipated that this invention may be used in the preparation ofthe edges of can body blanks. To clean the edges of can body blanks, asmall volume of liquid flowing under high pressure is required.

The power supply and control circuitry for the above apparatus is shownin the accompanying figures.

The schematic electrical circuit shown in FIG. 7 is designated to applyhigh electrical potential and amperage across the arcs in each of thepressure compartments. The switching arrangements of the switching unitsare such that the circuits apply electric potential sufficient to breakdown the gap between the electrodes and create heightened pressure toaugment the pressure wave as it passes from compartment to compartment,thus stepping up the pressure. It is readily apparent from FIGS. 7 and 8that any number of switching units 2530 having storage capacitors andelectrode pairs 3I-36 may be used corresponding to the number of stagesin the pump. The pulse generator 37 which is shown is applied to thetapped delay line 38. This delay line 38 includes both the tapped chargedelay line 39 and the tapped discharge delay line 40 shown in FIG. 8.The frequency of the pulse cycle determines the number of pressure waveswhich are to proceed down the fluid pressure buildup apparatus. One sideof the main power supply is connected to one electrode of each of theelectrode pairs 3136. In FIG. I, only three of these pairs are shown aselectrodes 7 and 8.

The application of electrical potential is accomplished by means of themain power supply which charges capacitors in the switching units 25-30.Individual switches 4l46 (FIG.

8) are provided in each of the switching units for switching the storagecapacitor to charge and switching the storage capaci tor to dischargethrough the individual arcs located in each of the chambers. The delayline 38 and through the delay line the switches are operated by asynchronous signal conducted through a pulse generator to give rise to asignal strong enough to operate tapped delay line 38.

A more detailed showing of the power supply is given in FIG. 8 exceptthree of the switching units and related equipment shown in FIG. 7 aredeleted in FIG. 8. A main power supply or primary source of directcurrent 47 delivers a terminal voltage [5 across its terminals.Connected across these terminals is a charging resistor 48 having aresistance of R ohms and considerable wattage capacity. Switch 44 ismounted in series with the energy storage capacitor 49 and chargingresistor 48 across the main power supply 47. Similarly, switch 45 ismounted in series with the charging resistor and a second energy storagecapacitor 50 and so on down the line to the last switch 46 mounted inseries with the energy storage capacitor 51. The each individualcircuit, the switch, storage capacitor and primary power supply areconnnected in electrical series. Thus, several energy storage capacitorsare mounted in parallel with their respective switches across theprimary DC supply. In this way, the energy storagecapacitors are beingcharged at varying initial times, the drain on the primary electricalsupply is almost constant, and the voltage E, is not substantiallyreduced.

In the operation of this circuit, the charging and discharging is takingplace in a more or less continuous fashion as the pressure wave proceedsdown through the various stages of the electrohydraulic pump. Whenswitch 44 is closed by an impulse from the charge delay line 39, thevoltage on the capacitor 49 is initially zero and at any time afterswitch 44 is closed, this voltage is given by the equation:

wherein E equals the instantaneous voltage, E equals the voltage acrossthe primary supply, I equals the time the voltage E has been appliedacross the capacitor, R equals the resistance, and Cequals thecapacitance in the circuit.

In a similar fashion, thecapacitors 49, 5t) and 51 charge when theirrespective switches 44, 45 and 46 are closed by the charge delay line39.

Switches 4I-43 together with switches 4446 are typically heavy switchescapable of conducting the necessary current and may be an ignatronhydrogen thiratron or solid state device of the Silicone ControlledRectifier type. In any case, the switches are switched to the on orconducting position for application of the suitable potential and areturned off by removal of the potential. When the capacitors 49, 5t) and53 are being simultaneously charged, ganged switches 51, 54, 55 areswitched to the upper alternate position shown in FIG. 8 to causeswitches 44, 45, 46 to close when a synchronization signal is appliedfrom the pulse generator to the charge delay line. However, in theoperation of my device, it is intended that sequential operation of theswitches 44, 45, 56, is to be accomplished thereby causing the chargingcircuit of the capacitors 49, 50, 51 to operate in a staggered orsequential fashion through the use of a suitable delay line composed ofa series of equal valve capacitors 56, 57, 59, and equal valve inductors59, 60, 61 shown in FIG. 8 when the switches 52-55 are in position shownin FIG. 8.

The capacitors and inductances in the charge delay line and thedischarge delay line are of equal value to give equal timed delays.Either the discharge delay line or the charge delay line may have aninductor of one-half the value of the sector inductance to delay thepulse in one line so that the switches cause each capacitor to chargeand discharge in a phased relationship.

A schematic of the control part of the charge delay line is shown inFIG. 9. This line is shown having equal effective inductances in eachsection and equal effective capacitors in each section. It is terminatedby a resistance 62 having a resistance equal to the characteristicimpedance of the line. In the case where equal intervals of time aredesired between switchings, then a pulse of proper length is applied atthe input terminals 63, 64 from a matched voltage source and ispropagated along the line with a constant velocity until it reaches theterminating resistor 62 where the power is absorbed. If the line istapped at a number of places as shown in FIG. 9, the pulse voltage willappear at successive times at each tap along the length of the line.Such a voltage is used to actuate switches 44, 45, 46 at each chargingelement. The overall result is that energy is delivered to a number ofdifferent physical locations according to a predetermined and repeatabletimed sequence while using the charge delay line to control amultiplicity of individual switches.

The total delay time for single line section is approximately:

V TI: l l

wherein L, is the inductance in the sector, and C, is the capacitance inthe sector.

The sequential discharge of capacitors 49, 50, 51 (FIG. 8) may beaccomplished by operating switches 41, 42, 43 through a sequentialdischarge delay line which operates on exactly the same principle asexplained in regard to the charge delay line. The discharge delay lineand charge delay line are, however, out of phase so that suitableelectrical energy may be stored in capacitors 49, 50, 51. Whatever leadtime is necessary between the charge delay line and discharge delayline, the discharge delay line must fire or send an impulse to itsrespective switches at spaced intervals so that the pressure wavepassing from compartment to compartment is augmented in each compartmentto give a resultant high-pressure volume flow of liquid through theelectrohydraulic sonic pump.

The foregoing are descriptions of illustrative embodiments of theinvention, and it is applicant's intention in the appended claims tocover all forms which fall within the scope of the invention.

What I claim is:

1. An electrohydraulic high-pressure, low-flow pumping apparatuscomprising:

a series of chambers of approximately equal size and shape having fluidmeans therein;

elastomeric diaphragm means mounted across each chamber to form a firstand a second compartment; pressure-transmitting liquid filling saidfirst compartment; means providing a conduit from said first compartmentto at least one other first compartment; one-way valve means in eachsaid conduit means for allowing said fluid pressure to pass through saidseries of compartments in one direction;

means including spaced electrodes in each second compartment for raisingthe fluid pressure in said second compartment; f

electrode surrounding liquid filling said second compartment:

first conduit means connecting each said electrode compartment to a pumpfor pumping said electrode surrounding liquid to said compartment;

second conduit means connecting said first compartment to a liquidreservoir whereby said first compartment is kept filled withpressure-transmitting liquid;

electrical means for intermittently applying electric potential acrosssaid spaced electrodes and synchronizing the operation of saidpressure-raising means in each chamber with that of each other chamberso that an ultimate pressure wave is generated in the end chamber ofsaid series and is reinforced by said pressure-raising means in eachchamber as the wave travels through said series of chambers. 2. Anelectrohydraulic high-pressure, low-flow pumping apparatus as set forthin claim I in which said one-way valve means comprises:

a flap valve. 3. An electrohydraulic pumping apparatus comprising:

a series of chambers of approximately equal size and shape having afluid therein;

means providing a conduit from each said chamber to at least one otherchamber;

one-way valve means in each said conduit means for allowing said fluidpressure to pass through said series of chambers in one direction;

paired means including a first and second electrode spaced from eachother in each chamber for raising the fluid pressure in said chamber;

a plurality of means for applying voltage across each pair of electrodesin sequence, each said means of said plurality comprising:

a storage capacitor having first and second terminals;

a means for charging said storage capacitor on a periodic basis to apredetermined potential;

first connecting means for electrically connecting said first terminalof said capacitor to said first electrode;

a first switch having a first and second terminal and a control elementfor opening andclosing said switch;

second connecting means for electrically connecting said first terminalof said switch to said second terminal of said capacitor;

third connecting means for electrically connecting said second terminalof said switch to said second electrode; and

a first L-C delay discharging circuit means for operating each saidswitch control element to open and shut each said switch of each of saidplurality of voltage-applying means in a timed relationship.

4. An electrohydraulic pumping apparatus as set forth in claim 3 inwhich said means for electrically charging said storage batterycomprises:

a source of direct current having a first and a second externalterminal;

a second switch having a first and second terminal and a control elementfor opening and closing said switch;

fourth connecting means for electrically connecting the first terminalof said switch to the second terminal of said capacitor;

fifth connecting means for electrically connecting the second terminalof said switch to the first terminal of said direct current source;

sixth connecting means for electrically connecting the first terminal ofsaid capacitor to said second terminal of said direct current source;and

a second L-C delay discharge circuit means for operating said switchcontrol element to open and shut said switch in timed synchronism withsaid first L-C delay discharging circuit means whereby said capacitorcharges and discharges at different times.

5. An electrohydraulic pumping apparatus as set forth in claim 3 inwhich said first L-C delay discharging circuit means comprises:

a means for operating each said switch control element to shut saidswitch of each of said plurality of voltage applying means in a sequencewhereby the fluid pressure in successive chambers is raised just at thetime that the pressure wave from the preceding chamber has arrived andthe magnitude of the pressure wave is increased by successive incrementsbeing added in successive chambers.

1. An electrohydraulic high-pressure, low-flow pumping apparatuscomprising: a series of chambers of approximately equal size and shapehaving fluid means therein; elastomeric diaphragm means mounted acrosseach chamber to form a first and a second compartment;pressure-transmitting liquid filling said first compartment; meansproviding a conduit from said first compartment to at least one otherfirst compartment; one-way valve means in each said conduit means forallowing said fluid pressure to pass through said series of compartmentsin one direction; means including spaced electrodes in each secondcompartment for raising the fluid pressure in said second compartment;electrode surrounding liquid filling said second compartment: firstconduit means connecting each said electrode compartment to a pump forpumping said electrode surrounding liquid to said compartment; secondconduit means connecting said first compartment to a liquid reservoirwhereby said first compartment is kept filled with pressure-transmittingliquid; electrical means for intermittently applying electric potentialacross said spaced electrodes and synchronizing the operation of saidpressure-raising means in each chamber with that of each other chamberso that an ultimate pressure wave is generated in the end chamber ofsaid series and is reinforced by said pressure-raising means in eachchamber as the wave travels through said series of chambers.
 2. Anelectrohydraulic high-pressure, low-flow pumping apparatus as set forthin claim 1 in which said one-way valve means comprises: a flap valve. 3.An electrohydraulic pumping apparatus comprising: a series of chambersof approximately equal size and shape having a fluid therein; meansproviding a conduit from each said chamber to at least one otherchamber; one-way valve means in each said conduit means for allowingsaid fluid pressure to pass through said series of chambers in onedirection; paired means including a first and second electrode spacedfrom each other in each chamber for raising the fluid pressure in saidchamber; a plurality of means for applying voltage across each pair ofelectrodes in sequence, each said means of said plurality comprising: astorage capacitor having first and second terminals; a means forcharging said storage capacitor on a periodic basis to a predeterminedpotential; first connecting means for electrically connecting said firstterminal of said capacitor to said first electrode; a first switchhaving a first and second terminal and a control element for opening andclosing said switch; second connecting means for electrically connectingsaid first terminal of said switch to said second terminal of saidcapacitor; third connecting means for electrically connecting saidsecond terminal of said switch to said second electrode; and a first L-Cdelay discharging circuit means for operating each said switch controlelement to open and shut each said switch of each of said plurality ofvoltage-applying means in a timed relationship.
 4. An electrohydraulicpumping apparatus as set forth in claim 3 in which said means forelectrically charging said storage battery comprises: a source of directcurrent having a first and a second external terminal; a second switchhaving a first and second terminal and a control element for opening andclosing said switch; fourth connecting means for electrically connectingthe first terminal of said switch to the second terminal of saidcapacitor; fifth connecting means for electrically connecting the secondterminal of said switch to the first terminal of said direct currentsource; sixtH connecting means for electrically connecting the firstterminal of said capacitor to said second terminal of said directcurrent source; and a second L-C delay discharge circuit means foroperating said switch control element to open and shut said switch intimed synchronism with said first L-C delay discharging circuit meanswhereby said capacitor charges and discharges at different times.
 5. Anelectrohydraulic pumping apparatus as set forth in claim 3 in which saidfirst L-C delay discharging circuit means comprises: a means foroperating each said switch control element to shut said switch of eachof said plurality of voltage applying means in a sequence whereby thefluid pressure in successive chambers is raised just at the time thatthe pressure wave from the preceding chamber has arrived and themagnitude of the pressure wave is increased by successive incrementsbeing added in successive chambers.